1. Field of the Invention
The present invention resides in a process for selectively producing trimethylbenzene by gas phase reaction of a C.sub.1 to C.sub.4 alkane with magnesium to produce a reaction product. The reaction product is subjected to a protonolysis reaction with either water or an alcohol to produce a reaction mixture. Finally, the reaction mixture or a fraction thereof, thus produced, is contacted with a metal containing Y zeolite catalyst under reaction conditions.
Trimethylbenzene occurs naturally in petroleum reformate as its three isomers, namely, pseudocumene (1,2,4 trimethylbenzene), mesitylene (1,3,5 trimethylbenzene) and hemimellitene (1,2,3 trimethylbenzene), but only pseudocumene can be isolated from the petroleum reformate in high purity with a reasonable yield due to distillation limitations. Additionally, trimethylbenzene is produced commercially in the petroleum industry by catalytic reforming and catalytic cracking operations usually involving straight run naphthas.
More recently, trimethylbenzene has been produced in the United States by the Koch Company, utilizing what is commonly known as the Koch Process. This process is based on alkylation, isomerization and disproportionation reactions which are conducted in the presence of a Friedel-Crafts Catalyst. For example, benzene is reacted with an alkylhalide or an alkyl alcohol in the presence of aluminum chloride to prepare an alkylated benzene.
Generally, trimethylbenzene has previously been used as a blending stock for gasoline and aviation fuel because of its unique octane enhancing property. Trimethylbenzene may be converted to sterically hindered phenols which are utilized as non-coloring stabilizers (antioxidants) for plastics, adhesives, rubber and waxes. It should be noted that the isomeric trimethylbenzenes are valuable intermediates for the production of many organic compounds including acids, ketones and the like. In addition, trimethylbenzene is useful as a dye intermediate (e.g., as 2,4,6 trimethylanaline) and as a perfume additive.
2. Description of the Prior Art
Processes and catalysts for the production of substituted aromatic compounds from relatively low molecular weight hydrocarbons are known and are currently practiced commercially.
For example, U.S. Pat. No. 3,204,008, issued August 31, 1965, relates to a process for preparing aromatic compounds from acetylenically unsaturated compounds using a catalyst consisting of mixtures of the halides of tantalum, or of the halides or oxyhalides of niobium or of mixtures thereof.
U.S. Pat. No. 4,009,219, issued February 22, 1977, relates to a method for producing benzene wherein non-hydrocarbon carbonaceous raw materials are reacted with an alkali metal or an alkaline earth metal to produce a metallic carbide. The metallic carbide is hydrolyzed to produce acetylene and the acetylene is cyclized to benzene using a chromium VI or vanadium VI activated silica-aluminum catalyst.
U.S. Pat. No. 4,172,810, issued October 30, 1979, discloses catalyst compositions which are described as suitable for the conversion and oligomerization of hydrocarbons, in particular, methane to produce ethylene or benzene. The catalyst consists of an inorganic-oxide support, preferably alumina, composited with the Group IB, IIA, VIB or VII metals and barium.
U.S. Pat. No. 4,205,194, issued May 27, 1980, relates to a process for the conversion and oligomerization of hydrocarbons, notably methane to produce ethylene or benzene. The process utilizes a catalyst consisting of an inorganic-oxide support, for example, alumina, composited with the Group IB, IIA, VIB or VIII metals.
Canadian Pat. No. 595,668, issued April 5, 1960, discloses a process for the polymerization of acetylenic compounds, wherein the acetylenic compound is brought into contact with a reaction medium consisting of an organo-compound reacted with at least one non-transition metal of Groups I, II and III, and a compound of a transitional metal.